Celica Supra L6-2759cc 5M Ser (1982)
Thermal Vacuum Valve: Testing and Inspection
Thermo Sensor
1. On 1980 20R engine, check electrical wiring as follows:
a. Disconnect hose from lower port of air injection vacuum switching valve and connect vacuum gauge to port.
b. Warm up engine to operating temperature. Gauge should indicate high vacuum at idle.
c. Short terminals of thermo sensor. Gauge should indicate little or no vacuum at idle.
2. On all 1978-82 models equipped with thermo sensor, measure resistance as follows:
a. Unplug wiring connector.
b. Measure resistance between terminals at idle. Resistance should be 2 to 200 kilo ohms with engine at operating temperature.
CAUTION: The ohmmeter test probe should be inserted from the rear side of connector.
c. Reconnect wiring connector and check wiring of sensor for damage or loose connections.
